Aspergillus oryzae in solid-state and submerged fermentations. Progress report on a multi-disciplinary project.

Area of Science:

• Biotechnology
• Microbiology
• Biochemistry

Background:

• Filamentous fungi like Aspergillus oryzae are crucial in biotechnology.
• Solid-state fermentation (SSF) and submerged fermentation (SmF) offer different growth environments.
• Understanding fungal responses to these conditions is key for optimizing bioprocesses.

Purpose of the Study:

• To compare the molecular and physiological differences of Aspergillus oryzae in SSF versus SmF.
• To identify fungal adaptations to solid-state growth conditions.
• To leverage these insights for improved biotechnological applications.

Main Methods:

• Comparative analysis of Aspergillus oryzae under SSF and SmF conditions.
• Monitoring of physiological parameters such as oxygen uptake and nutrient gradients.
• Analysis of gene expression and protein secretion patterns.

Main Results:

• Aerial hyphae in SSF are critical for oxygen uptake.
• SSF environments exhibit gradients in temperature, water activity, and nutrients, leading to polyol accumulation.
• Distinct gene expression and protein secretion profiles were observed between pelleted growth in SmF and mycelial growth in SSF.

Conclusions:

• Aspergillus oryzae exhibits significant physiological and molecular adaptations to SSF compared to SmF.
• These findings provide a deeper understanding of fungal behavior on solid substrates.
• The research paves the way for enhanced biotechnological utilization of SSF.